Plastic composition



' ponents to the Patented May 6, 1924.

T E S PATENT orrice.

WILLIAM G. INnsAY, or NEWARK, NEW JERSEY, AssIoNoR TO THE oELLuLoID COMPANY, A CORPORATION OF NEW JERSEY.

PLASTIC 'ooMrosIrIoN.

No Drawing. Original application filed April 25, 1922, Serial Ila-556,530. Divided and this application filed March l3, 1923. Serial No. 624,700.-

To all whom it may concern:

Be it known that I, WILLIAM a citizen of the United States, Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Plastic Compositions, of which the following is a specification.

This invention. relates to a process for rendering certain inflammable materials, substance, or compounds, non-inflammable, and to the preparation of commercially useful' non-inflammable articles, such as paper, textile fabrics, cellulose plastics, pyroxylin plastics and the like.

The degree of non-inflammability sought for is that which will,not permit of a self sustaining combustion, after the application of a flame at ordinary or normal temperature. This degree of non-inflammability will however, be varied according to desired conditions.

I have discovered that inflammable materials which permit of a self sustaining combustion by the application of a flame at ordinary or normal temperature may beprevented from burning under ordinary conditions andrendered non-inflammable pro vided there is present in suitable combination a heat absorbing compound capable of absorbing or taking up through decomposition, volatilization, or other change, all or the major part of the heat thatwould be necessary to raise the material "or its compointat which ignition could G. LINDSAY,

be sustained.

This heat absorbing, or endothermic, substance or compound should be of such nature that it will decompose, or otherwise be in condition to absorb heat, before or when the temperature of combustion of the material to be rendered non-inflammable has been reached. The absorption of heat will thus proceed at such a rate as to prevent the combustible material from attaining its temperature of ignition. The endothermic substance or compound will also be selected having in view other characteristics besides its heat absorbing capacity on decomposition in that it may be desired toimpart other properties to the resultant product. The =relative proportions of the combustible substance, i. e., the substance to be rendered non-inflammable, and endothermic or heat residing at absorbing substance, will be varied somewhat to meet conditions of strength, plasticity, transparency, acteristics, but in general will be dependent upon the amount of decomposition, in heat unit equivalents, that can take place at or below the temperature at which combustion could be sustained by the exothermic compound if the heat of combustion were not absorbed at a greater rate than that at which it could be liberated. The general rule is that a suflicient quantity of endothermic substance should be employed to absorb upon its decomposition at a temperature below the ignition point of the exothermic sub stance, a sufficient amount of heat to prevent a sustained combustion of the said exother mic substance.

In carrying outmy invention, a number of products may be the aim. The characteristics of these products may vary from that of a. hard, nonmoldable, dense solid sheet material which may be used for cutting out various objects such as brush backs, mirror backs, knife handles, etc., to that of a thin, highly flexible product which may be used for the coating of fabrics, paper and the like or which can be used in place of various textiles and other flexible materials.

any one of The flexible compound may also beused as a substitute for leather. It may also possess the necessary characteristics required in compounds that are tobe molded such as molded boxes, molded handles, molded brushes, mirrors, etc.

In carrying out the invention the procedure will vary according to the nature and physical properties of the material treated. The exothermic substances which I propose to'use will be nitrocellulose, acetylcellulose, or some cellulosic ester, ether, derivative, or compound.

The permanent or generally referred to as the plasticizing agents and which are tobe combined with the pyroxylin or other cellulose derivative for the purpose of bringing about the necessary conversion, etc. in the course of manufacture, should be of such nature that the point of ignition is experiments I have found that the organic phosphates possess the necessary characterlstics of solubility and at possess the requisite temperature of ignition.

or other desirable charnon-volatile solvents relatively high. In my the same time To a mixture of nitrocellulose and an aro-.

matic phosphate, as for example, liquid tri- .cresylphosphate, I add a suficient amount of calcium sulphate to prevent the combined mixture from sustaining ignition upon the application and withdrawal of a flame. An

example of proportions for this purpose is 100 parts of acetylcellulose, 30 parts of liq uid tricresylphosphate and 50 parts of calcium sulphate, (CaSOQI-I O). Material of this composition, when manufactured according to the usual methods as obtained in the pyroxylin plastic industry, will possess hardness, toughness and moldability in similar degree to the usual varieties of celluloid, manufactured in the form of ivory, opaque colors and the like.

In the manufacture of these non-inflammable compounds I proceed substantially as in the manufacture of ordinary pyroxylin plastic materials incorporating the calcium sulphate compound with the soaked or colloidized mass of pyroxylin and liquid tricresylphosphate prior to final mastication on the rolls. This incorporation may be effected in kneaders or the calcium sulphate compound may be directly added during the course of mastication on the rolls. The calcium sulphate compound may also be incor: porated with the pyroxylin or cellulose aceta-te in the same operation in which the liquid tricresylphosphate is incorporated, the

method for which is described in my U. S. Patent No. 1,233,374, granted July 17, 1917.

In the choice of liquid volatile solvent, I may select any one or a combination of a number of the common ordinary solvents, such as methyl alcohol, ethyl alcohol, acetic ether, acetone, amyl acetate, or the various aeaaoe commercial grades and mixtures of these compounds as are ordinarily found upon the market. v

1 In themanufacture of the flexible non-inflammable compound having the properties of leather and the like, I proceed as in the example specified except that I use a some what greater proportion of liquid tricresylphosphate. Material of this composition may be Worked up according to the usual method for the manufacture of pyroxylin plastic compounds and produced in the form of sheets by shaving from a block,vor it may be dissolved in a suitable proportion of solvent such as Wood alcohol, acetone, and the like and spread upon a suitable surface such as a textile fabric, leather and the like.

This application is a division of my application Ser. No. 556,530, filed April 25, 1922.

physical properties of the usual pyroxylin plastics, said composition having as a base' acetyl cellulose plasticized by an aromatic phosphate and as a fire retarding ingredient a heat absorbing salt of calcium.

' 5'. A composition having substantially the physical properties of the usual pyroxylin plastics, said composition having as a base plasticized acetyl cellulose and as a fire retarding ingredient calcium sulphate.

WILLIAM G. LINDSAY. 

